"The LEDR.com website includes a feature for testing display screens, including a black screen check. This tool is designed to help users assess the quality and performance of their display devices, particularly by displaying pure black to check for uniformity, backlight bleed, or dead pixels. For more details or to use the tool Website: https://www.ledr.com/colours/white.htm Address: 1808 Hot Springs Ave, Cheyenne, WY 82001, Hoa Kỳ Phone: 13076325872 Email: wporter@ledr.com #Screen , #Backgroun